Syncope and near-syncope are great diagnostic challenges in medicine.
On the one hand, the symptom may result from a benign condition and pose little
or no threat to health other than that related to falling. On the other hand,
syncope or near-syncope can be the manifestation of a serious underlying condition
that poses an imminent threat to life. Patients with a cardiac cause of syncope
are at far greater risk of dying in the first year after an episode of syncope
or near-syncope than individuals with a noncardiac cause. A cardiac cause
of syncope should be considered in every patient with syncope or near-syncope,
but it is particularly common in older patients or in patients with known
structural heart disease, arrhythmia, or certain electrocardiographic abnormalities.
Although many diagnostic tests may be helpful in the evaluation of syncope
and near-syncope, the history, physical examination, and electrocardiogram
pinpoint the cause in many circumstances. Syncope after exercise may be due
to left ventricular outflow tract obstruction from aortic stenosis or hypertrophic
obstructive cardiomyopathy but can also suggest the diagnosis of postexercise
hypotension in which an abnormality in autonomic regulation of vascular tone
or heart rate results in vasodilation or bradycardia after moderate-intensity
aerobic activity. The patient discussed in this case highlights the importance
of the clinical history in the evaluation of this condition, since the diagnosis
was revealed as the patient's story was described and eventually acted out.